nounEtymology: Middle English, from Old English, from Late Latin, from Greek rhabbi, from Hebrew rabbī my master, from rabh master + -ī myDate: before 12th century1.master, teacher — used by Jews as a term of address
2. a Jew qualified to expound and apply the halakah and other Jewish law
3. a Jew trained and ordained for professional religious leadership; specifically the official leader of a Jewish congregation

rabbi — (n.) Jewish doctor of religious law, late 15c. (in Old English in biblical context only; in Middle English also as a title prefixed to personal names), from L.L. rabbi, from Gk. rhabbi, from Mishnaic Heb. rabbi my master, from rabh master, great… … Etymology dictionary